Brush unit and drive means therefor



Oct. 3, 1961 J. c. BONGIOVANNI BRUSH UNIT AND DRIVE MEANS THEREFOR 4 Sheets-Sheet 1 Filed July 25, 1955 INVENTOR. J0///V. CBfl/VG/OVA/VN/ A TTOR/VEXS.

Oct. 3, 1961 .1. c. BONGIOVANNI 3,002,503

I BRUSH UNIT AND DRIVE MEANS THEREFOR Filed July 25, 1955 4 Sheets-Sheet 2 INVENTOR. /9 4729. 2 JOHN c. EW/YG/OI/A N/V/ Oct. 3, 1961 Filed July 25, 1955 J. C. BONGIOVANNI BRUSH UNIT AND DRIVE MEANS THEREFOR REVERSE v.

Fi955 25a 3 v 95 a o ESA r 93 4 Sheets-Sheet 5 FIG. 4

INVENTOR. JOHN C. BOFBIOVANNI m; MM

ATTORNEYS Oct. 3, 1961 Filed July 25, 1955 FIG. 5

J. C. BONGIOVANNI BRUSH UNIT AND DRIVE MEANS THEREFOR 4 Sheets-Sheet 4 INVENTOR.

JOHN C. BOFBIOVANNI AT TORNEYS Without interrupting operation of the line.

United States Patent 3,002,503 BRUSH UNIT AND DRIVE MEANS THEREFOR John C. Bongiovanni, University Heights, Ohio, assignor to The Osborn Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Filed July 25, 1955, Ser. No. 524,115 4 Claims; (Cl. 121-45) This invention relates as indicated to a brush unit and drive means therefor, and more particularly to a power driven rotary brush stand adapted to the processing of continuously traveling metal strip and the like.

In the surface conditioning and cleaning of metal articles, and particularly elongated articles such as strip metal, rod and Wire, rotary brushes have been utilized to a rather limited extent for the removal of mill scale from hot rolled stock and also to produce a desired finish on the Work. Acid pickling is generally relied upon for complete removal of scale, however, although sand and shot-blasting and hot hydride methods have been employed to some extent.

Acid pickling methods are quite effective in removal of oxide scale, but they also involve the removal of some good metal unless so inhibited as greatly to slow the operation and do not assist in reducing slivers, burrs, and other surface irregularities. The pickling acids preferentially attack certain portions of the metal surface, thus producing numerous weakening and otherwise objectionable pits, and hydrogen liberated as the acid does its work is adsorbed into the steel or other metal to a considerable extent with some resultant embrittlement of the metal. Despite subsequent washing operations, minute amounts of the pickling solution or resultant salts and other water-borne materials, after drying, tend to remain in such small pits and surface irregularities where they may subsequently cause considerable trouble. Sulphuric acid is the acid most usually employed, and the supply is not always as stable as might be desired.

Reference may be had to the co-pending application of Ruben 0. Peterson, Serial No. 491,992, filed March 3, 1955, entitled, Reciprocating Surface-Finishing Mechanism and Method, for a more detailed explanation of the advantages of power brushing metal workpieces such as strip, rod and the like for removal of mill scale and also for providing a desired surface finish. The brushing mechanism of my invention is generally similar to that disclosed and claimed in such Peterson application but embodies certain novel and advantageous features as explained below.

The usual brush material employed is hard steel wire which may be modified in several ways and is very effective for the purpose intended. After a certain period of operation, however, with the brush turning in one direction, the wire bristle ends comprising the working face of the brush tend to become rounded and smoothed on their sides, with resultant drastic reduction in eifectiveness. For this reason, it is desired periodically to reverse the direction of rotation of the brushes thereby to render them substantially self-sharpening and obtain uniformly effective brushing action. Such brush reversal may desirably be caused to take place at the conclusion of a brushing operation. On such occasions, the brush will be out of contact with the work and there will ordinarily be no great necessity for causing the reversal to take place in a minimum period of time. When brushing elongated work-pieces, however, such as rod, strip and the like, and especially when one length is welded or tacked to the end of a succeeding length, opportunities for brush reversal in this manner are far too few, and it becomes important to provide means for frequently reversing the direction of rotation of the brush It is accord- 3,062,593 Patented Oct. 3, 1961 'ice Another object is to provide control means for such drive means effective to actuate such brush reversing means at timed intervals.

A further object is to provide brush mounting means including such drive means adapted for speedy removal of the brush and associated parts from the stand to permit changing of brushes with a minimum of line down time.

Still another object is to provide brush mounting means permitting removal of a cylindrical power driven rotary brush from its supports \m'thout the necessity of dismantling an end bearing.

Other objects of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

FIG. 1 is a vertical sectional view through the brushes of a brushing stand embodying the principles of my invention intermediate the two end frame members supporting such brushes;

FIG. 2 is a vertical transverse section taken on the line 22 on FIG. 1;

FIG. 3 is a fragmentary detail view, partly in section, of the brush stand reciprocating mechanism;

FIG. 4 is a fluid pressure diagram of the brush drive means and associated control mechanism; and

FIG. 5 is a schematic wiring diagram of the electrical control system operating in conjunction with such fluid pressure system.

Now referring more particularly to said drawing and especially FIGS. 1-3 thereof, the embodiment of my invention there illustrated comprises two end frame members 1 and 2 having windows or vertical slideways 3 and 4 therein. Such side frame members 1 and 2 are joined together by tie rods 5, 6, 7 and 8 enclosed within spacer tubes 9, lo, 1 1 and 12. This stand is in turn mounted on a carriage 13 having rollers such as J14, 15 and 16 resting on rails 17 and 18 for reciprocation of carriage 13 therealong. Rails 17 and 18 are mounted on a stationary base frame 19. As shown in FIG. 3, a double-acting fluid pressure cylinder 20 is mounted on a horizontal pivot on stand 21 with piston rod 22 pivotally connected to the end of carriage 13 whereby such carriage may be reciprocated back and forth on a controlled path transversely of the path of travel of metal strip S through the brushing stand. The reciprocation of the brushing stand will be regulated in the manner more fully described and explained in the above-identified Peterson application Serial No. 491,992 to bring the respective ends of the brushes alternately closely adjacent the corresponding side edge of the strip, thereby to ensure relatively even wear of the brush faces and uniform action on the work. Such reciprocation of the brushing stand is, of course, not per se a part of the present invention but will desirably be utilized in conjunction therewith.

Lower slides 23 and 24 are fitted within vertical slideways 3 and 4 respectively and removably retained therein by means of keeper plates 25 and 26 which may be secured by bolts such as B in slots C for release and lateral shifting movement. Slide 23 is supported on screw jack 27 adapted to be rotated through worm and worm gear unit 28, and slide 24 is supported by screw jack 29 adapted to be rotated through worm and worm gear unit 30. A reversible electric motor 31 carried on lower crosspiece 32 of carriage 13 is operative to drive a worm and worm gear reduction unit 33 coupled to worm and Worm gear units 28 and 36 to raise and lower jacks 27 and 29 in unison.

A power driven rotary brush which may comprise a cylindrical shell 34 having annular end members 35 and 36 is mounted on straight hub 37 and tapered hub 38 keyed to shaft 39 journalled in bearings 40 and 41 in slides 23 and 24- respectively. The brush material 42 will ordinarily be wire bristle material which may be in the form of brush strip wound upon cylindrical shell 34, such brush strip itself preferably being constructed in the manner shown and described in Patent No. 2,303,386 to Ruben 0. Peterson. Split retainer plates 43 and 44 are secured by means of machine screws threaded into hub members 37 and 38 respectively and serve to secure annular brush end members 35 and 36 properly seated on such hubs.

A hollow outboard bracket or housing 47 is mounted on slide '24 and encloses the end of brush shaft 39 coupled to the drive shaft 48 of a fluid motor 49 having inlet and outlet ports 50 and 51.

An upper brush 52 of a construction identical to that of lower brush 53 is mounted directly above the latter, its shaft 54 being journaled in bearings 55 and 56 releasably secured in upper slides 57 and 58 respectively. Four pneumatic cylinders such as 59 and 60 are mounted in lower slides 23 and 24 with pistons such as 61, 62 and 63 extending upwardly therefrom to engage the undersides of upper slides 57 and 58. It will accordingly be seen that when jacks 27 and 29 are operated to lower slides 23 and 24, the upper brush 52 will not be permitted to descend therewith. Adjustment of such jacks (and also the upper jacks described below) in conjunction with adjustment of the pressure in the pneumatic cylinders such as 59 and 60 serve both to locate the brush relative to the work pass and also to regulate the pressure of such brushes'against the respective upper and lower surfaces of the work. Upper screw jacks such as 64 and 65 bear against the upper surfaces of slides 57 and 58 respectively and are adapted to be rotated through worm and worm gear units 66 and 67 respectively. Such gear units are driven by reversible electric motor 68 mounted on a bridge 69 carried by upper spacer tubes 9 and 10, through worm gear reduction unit 70. Appropriate operation of motor 68 is accordingly eflective to advance or retract screw jacks 64 and 65 in synchronism to permit slides 57 and 58 with upper brush 52 to rise or drop accordingly.

A hollow outboard bracket or housing 71 is mounted on upper slide 58 and carries a fluid motor 72 coupled to brush shaft 54 and having fluid inlet and outlet ports 73 and 74.

Each brush may be partially enclosed within a sheet metal hood such as 75 and 76 extending between the respective slides carrying the brush. As best shown in FIG. 1, such housings are, of course, open on the sides toward the work to expose the brush faces for contact with the respective sides of the traveling strip or the like. Suction means may be connected to such hoods, if desired, to withdraw scale particles and other material detached from the work surfaces by the high speed power driven rotary brushes.

The lower brush and its associated slides and housing may be removed from the stand after removal of keeper plates 25 and 26, and the upper brush together with its slides and housing may similarly be removed after removal of keeper plates 77 and 78. Inasmuch as the fluid motors are mounted on brush supporting slides, such motors will likewise be removed from the stand with the brushes, it being necessary only to disconnect the fluid pressure lines leading thereto. The slide, motor, and brush assembly will desirably be withdrawn from the stand in the same general manner employed in the removal of steel mill rolling mills. A tubular arm such as 79 or 80 properly counterweighted and carried by an overhead crane is sleeved onto the protruding end of the brush shaft and the entire assembly then withdrawn. The power driven screw jacks will, of course, first have been retracted to afI'ord maximum clearance. When a slide, motor, and brush assembly has been thus withdrawn and deposited on the mill floor, the outer bearing keeper ring (split) such as 81 or 82 will be removed and the corresponding end slide, e.g. '23, withdrawn from bearing 40, leaving such bearing assembled on shaft 39. Split retainer plate 43 is next backed off and removed and the brush housing shell 34 driven to the left as viewed in FIG. 2 to slide inner annular members 35 and 36 from their tapered seats on straight hub member 37 and tapered hub member 38 respectively. Tapered hub member 38 will be of slightly greater diameter than straight hub member 37 as viewed in FIG. 2 so that the outer shell 34 together with its integral inner annular members 35 and 36 may now be completely withdrawn from the assembly over bearing 40 without any necessity for disassembling the latter. A new brush shell filled with the desired brush material may quickly be put in place by a reversal of the abovedescribed procedure and the entire assembly reinstalled in the stand. Not only is there no necessity to disassemble end bearing 40, but also the driving connection between shaft 39 and fluid motor 40 need not be interrupted. Of course, in order to minimize down time of the line in which my new brush stand is a unit, it will generally be desirable to have one or more complete assemblies including slides, motor and brush ready for immediate replacement in the stand without the necessity of waiting completion of even the relatively simple brush renewal operation described above.

The employment of fluid motors 49 and 72 not only permits such motors to be mounted directly on the brush slide, but also facilitates up and down movement of such slides and reciprocation of the entire stand by pistoncylinder assembly 22, 20' inasmuch as such fluid motors are much smaller and lighter than conventional electric motor drives. While it is true that a primary power source must be provided in the form of a motor driven pump to supply fluid under pressure to the fluid motors, nevertheless a high pressure flexible hose may be utilized to connect such pumps and fluid motors so that the relatively heavy pumps and drive means therefor may be located in any convenient adjacent spot without the necessity of moving them when reciprocating the stand, adjusting the brushes, or replacing brushes. Moreover, as more fully explained below, such fluid motors are adapted to be very quickly stopped and reversed and remain constant in speed and smooth in operation once the desired rate of speed has been established. This is very desirable inasmuch as variations in speed tend to shadow mark the brushed product. The fluid motor is much more easily regulated to obtain the desired speed of rotation than is the usual direct electric motor drive. In the case of a hundred horsepower hydraulic motor unit, the speed range may be regulated at will from 1000 r.p.m. to 1900 rpm, for example, by a finger touch flow control valve. As previously indicated, it is desired to reverse the direction of rotation of the brushes rather frequently, and this may be accomplished in accordance with my invention through hydraulic braking and rapid hydraulic acceleration utilizing solenoid controlled valve means. I am enabled to reverse very large and heavy brushes rotating at several thousand r.p.rn. from full speed clockwise to full speed counterclockwise in from 2 to 4 seconds maximum elapsed time. Means may be provided for accomplishing such reversal automatically in synchronism with an accelerating or decelerating stage of the strip travel. If the strip is traveling approximately 30 feet per minute, I have found that it is ordinarily desirable to reverse the direction of rotation of the brushes about every five minutes, and proportionately more frequently when the strip is traveling at a speed offrom 100 to 200 feet per minute, for example. As contrasted toother braking and accelerating means, the acceleration and deceleration are smooth and without substantial shock to the drive means or the brush engaging the work. When thus reversing the direction of rotation of a brush while in engagement with the work, it will usually be desirable somewhat to relieve the pressure of the brush against the work during the brief interval required.

A suitable hydraulic motor for my purpose is manufactured by Dudco Division of the New York Air Brake Company, Hazel Park, Michigan. A suitable hydraulic oil is Harmony C. SAE-20 (300 S.S.U. at 100 F.) with anti-form, -rust and oxidizing agents and also including a Water emulsifier. A hydraulic motor to drive a cylindrical brush 20 inches in diameter and having a 12 inch wide brush face may be only /2 inches O.D. itself and the dual van core only 7 inches in diameter, resulting in a very low inertia (WR load. This factor is quite important with'regard to quick acceleration and deceleration of the brush. Such a hydraulic motor may weigh about 220 pounds. Of course, the hydraulic motor is entirely enclosed in its housing, making it impossible for scale and dirt to enter, whereas an electric motor must be permitted ventilation. It is this feature among others indicated which makes it feasible to mount the hydraulic motor directly on the slide adjacent the brush. This, of course, affords a much more compact arrangement and permits the provision of a much shorter base for the reciprocating stand, as contrasted to arrangements Wherein large electric motors and V-belt or chain drives must be mounted on the reciprocating base together with the brush stand. As explained in Peterson application Serial No. 491,992, it will frequently be desired to turn the brush stands at an angle to the path of work travel and obviously the shorter baseobtainable with my new construction will permit a series of stands to be thus arranged in sequence in angular relation to one another with a minimum of space required longitudinally of the line.

While, as indicated above, I prefer to employ ahydraulic motor to drive the brush because of certain advantages presented thereby over conventional type electric motors, it will be understood that my invention is not limited to use of such hydraulic motor but that an electric motor of suitable design, or for that matter any driving means' having the required characteristics, may be employed instead of the illustrated hydraulic motor.

The brush bristle material employed will ordinarily be .relatively hard crimped steel wire which may, for example, have a thin coating of nylon or other plastic thereon, and unless extremely hard wire is employed the bristle ends tend to become rounded and dulled on the sides first engaging the work, considerably reducing their effectiveness. This dilficulty may be substantially avoided by periodically reversing the direction of rotation of the brushes. If a sufiicient number of brushing stands are utilized, the brushes of one stand at a time may be tem porarily retracted out of contact with the work in order that they may be stopped and their direction of rotation thus reversed. Also, the brushes of an extra stand which have last been driven in one direction and have since been retracted from contact with the work may now be brought into operation again in the opposite direction to replace brushes of another stand due to be retracted and reversed, the newly retracted brushes becoming extras for similar subsequent employment. In some cases, however, it is quite satisfactory thus to reverse the rotation of the brushes while still in contact with the work or with contact pressure slightly reduced inasmuch as this can be achieved in a very short period of time. It is also often -=feasible to time such brush reersal in synchronism with changes in speed of travel'of the work and the passage of strip ends, for example.

' The apparatus and method described above have numerous advantages over conventional pickling methods ordinarily employed'in the removal of scale from strip and the like including the fact that there is little or no loss of virgin metal by a brushing as compared with from about /2% to as much as 2% metal oss often experienced during pickling. A brushing line of the general type described, including preliminary scale fracturing means and leveling means, will ordinarily occupy some- What less than one-half the space required by a pickling line. The pickling acid fumes are highly corrosive in the building and associated equipment and also make for unhealthful working conditions. Whereas the brushing line may be continuously maintained with only very brief periods of down time, a pickling line must periodically be completely shut down for relatively long periods to permit substantial replacements and repairs. The cost of the pickling acids, commonly sulphuric acid, has in the past fluctuated considerably more than has been the case with suitable brushing material. Not onlyis the suppyl of sulphuric acid sometimes a problem, but also the large quantities of water necessary are becoming steadily more difficult to obtain, especially reasonably clean water which will not leave objectionable residues. Whereas the waste disposal problem of a pickling line is serious and becoming steadily more so due to the imposition of anti-pollution laws, the scale removed by a brushing line is easily salvaged and becomes a valuable source of powdered metal for use in powder metallurgy. It'is also useful as an abrasive and as a chemical. The installation cost of a scale removal line of the general type disclosed herein may be as low as approximately one-third that of a continuous pickling line having the same production capacity.

Not only are there very important operating advantages arising from the employment of my new apparatus and process, but also the finished work is much superior to that obtainable from a conventional pickling line. More particularly, the brushing action, properly controlled, serves to beneficiate the metal surface by removal of minute splinters, the blending of sharp edges of pits, other surface irregularities and strip margins, and the production of a very clean, dry finish which does not tend to rust quickly. Despite the washing steps employed after acid pickling, it is not practical to remove all minute traces of acid, salts and Water-borne dirt from the metal surface, and consequently the pickled surface is not clean and is highly susceptible to rusting. The pickling process actually tends to produce and accentuate objectionable pits in the surface in which salts collect and a certain amount of hydrogen may be absorbed by the metal surface with consequent local weaknesses and embrittlement.

The brushing stands fit in well with other high speed equipment such as slitters, for example, and the brushing operations may, of course, be selected not only to remove scale but also to alford an improved finish to the metal surface, to remove edge burrs, and generally to eliminate the need for further elaborate finishing operations at a later period. In contrast thereto, the pickling line is often a bottleneck in a steel mill.

Referring now more particularly to the fluid pressure diagram FIG. 4, the system there illustrated comprises a sump or tank 83 and pumps 84 and 85 driven by electric motor 86 and adapted respectively to deliver hydraulic fluid under pressure to lines 87 and 88. Line 87 is adapted to be selectively connected to lines 89 and 90 respectively through a four-way solenoid operated valve 9 1, the coils of which are designated 91A and 91B.

This is a conventional type of valve having an open center connection in its de-energized condition and, as used here, when coil 91A is energized line 87 is connected to line 89 and line 90 to line 92; when coil 91B is energized, the valve is operated to connect line 87 to line 90 and line 89 to line 92, both such operating positions of course being accompanied by closure of the internal center connection. Thus, whichever line 89 or 90 is not connected with supply line 87 is connected through the same valve 91 to line 92 leading to a braking or pressure control valve 93 and thence back to the tank. Operation of valve 93 is, however, controlled by a solenoid valve 93A so that the former is eiiective only when it is desired to brake the hydraulic motor 49 to bring it to a stop prior to reversal of direction, as explained more in detail below. A pressure control and relief valve 94 is connected through a solenoid operated distributing valve 95 to determine the effective pressure obtainable in line 87. When valve 94 is thus operative, and pressure in line 87 rises above a preset figure, additional fluid will be diverted by such valve back to the tank. Moreover, as explained more in detail below, when valve 93 is effective to restrict return flow in line 90 back to the tank and thereby to brake hydraulic motor 49, valve 95 is operative to connect a relief head control valve 96 to line 87, such valve 96 permitting return flow to the tank at a greatly reduced pressure and thus rendering the braking action of valve 93 more effective. The two coils of valve 95 have been designated 95A and 95B, and the valve 95 is shown with a further direct connection to the return line to the tank, whereby this distributing valve can either completely by-pass control valve 94 or substitute relief head 96 in its stead. A flow control valve 97 is provided in another branch line 98, returning from line 87 to the tank, to permit regulation of the fluid flow (gallons per minute) through either line 89 or 90 to hydraulic motor 49, and thereby to regulate the speed of rotation of the latter.

In similar fashion, fluid pressure line 88 is adapted to be selectively connected to either line 98 or 99 leading to hydraulic motor 72 through solenoid controlled valve 100, the coils of the latter being indicated at 100A and 100B. Valve 101 corresponds to valve 93, solenoid controlled valve 101A corresponds to valve 93A, valve 102 corresponds to valve 94, solenoid controlled valve 103 (having coils 103A and 103B) corresponds to valve 95, relief head control valve 104 corresponds to valve 96, and flow control valve 105 corresponds to valve 97. The two hydraulic motors 49 and 72 are independently driven insofar as their respective fluid pressure systems are concerned but will normally be controlled to drive brushes 53 and 52 in opposite directions, thereby to engage the respective sides of the traveling work in the same direction.

Operation Referring now additionally to the electrical wiring diagram FIG. 5, wherein the pump motor and solenoid operated valves of the fluid pressure system of FIG. 4 have been included, the operation of the control system may now be explained.

Assuming the entire mechanism to be at rest, the operator will first throw double pole, single throw, fused disconnect switch 106. Closing of this main switch sets up the system for energization upon subsequent closing of manual push button switch 107. Upon thus closing switch 107, circuit 108 is energized including motor contactor 109, pilot lights D and 111, thereby starting pump motor 86. Overload contacts 112 and 113 are provided in this circuit to prevent overload of the motor. Accordingly, pumps 84 and 85 now deliver hydraulic fluid under pressure to lines 87 and 88 respectively. At this stage, however, fluid in line 87 will merely be returned through valve 91 and line 92 to the tank through normally opened valve 93A. Similarly line 88 is connected through valve 100 and normally opened valve 101A back to the tank.

Assuming that the brushes 52 and 53 are to be driven initially with their work-engaging faces moving in the same direction as the travel of the strip therebetween, selector switch 114 is set to automatic position closing, as indicated, contactor 114A in circuit 115. Next, push button switch 116 is manually closed to complete energization of circuit and control relay 117 therein. Closure of contacts 117A of relay 117 completes a circuit for energization of relay 118 to open contacts 118A of the latter and thereby de-energize ratchet relay 120, while at the same time closing contacts 118B to complete circuit 121. It will be seen that the circuit for such energization of relay 118 includes normally closed contacts 122D of relay 122, and that circuit 121 includes the normally open contacts 120D of the relay =120. Relay 131 is thus energized by circuit 121 and, through its contacts 131E completes a circuit for energization of relay 119. Closure of relay contacts 119A in turn results in energization of the relay 122.

Indicating light 123 was illuminated inasmuch as contacts 120A were closed as shown. Subsequent energization of relay 120 as above described, however, serves to open contacts 120A and close contacts 12013 to illuminate light 124 instead, as the hydraulic motors and brushes will now be rotated in directions opposite to those in which they were last previously turning.

Energization of relay 122 as noted above serves to close contacts 122A to condition circuits 125, 128, 129 and 130. Contacts 122B are closed to prevent inadvertent manual intervention within the subsequent automatic cycle, and contacts 122C are closed to condition circuits 125 and 126.

As noted, closure of contacts 118B produces energization of relay 131, and it will be seen that relay 132 in parallel therewith is likewise energized. Closure of contacts 131A completes the circuit 127 for energization of relay 137, contacts 1313 open in the circuit 125 to preclude energization of coil 103A of the solenoid valve 103, contacts 131C close to complete circuit 133 for energiza tion of the coil 103B of such valve, and contacts 131D close to complete circuit 134 for energization of the coil 141 of solenoid operated valve 101A. Contacts 131E close to provide the aforesaid energization of relay 119. Energizat-ion of relay 132 closes contacts 132A to energize relay 139, opens contacts 13213 in circuit 126 to the coil 95A of the solenoid operated valve 95, closes contacts 132C to complete circuit 135 to energize the coil 95B of this valve, closes contacts 132D to energize coil 142 of valve 93A, and closes contacts 132E to provide a parallel circuit for energization of the relay 119.

Valve 95 is thus operated to connect pressure regulating valve 94 with the line 87, and valve 103 is similarly operative to connect valve 102 with the line 88. Energization of relay 137 closes holding contacts 137A therefor and closes contacts 137B to complete circuit 138 for energization of the coil 100B of the valve 100. Energization of relay 139 closes its holding contacts 139A and through closure of contacts 139B completes circuit 140 for energization of coil 91B of the valve 91. The latter valve is thus actuated to place line 87 in communication with line 89, while such actuation of valve 100 places line 88 in communication with line 98. Energization of the coils 141 and 142 closes valves 101A and 93A respectively to remove the shunts provided thereby about regulating valves 101 and 93, whereby these valves are fully effective for their intended purpose.

Consequently, the two brushes 52 and 53 are now driven in opposite directions to engage the work passing therebetween in the same direction as the travel of such work. The brushes may thus be brought up to desired operating speed extremely rapidly, in as little time as two seconds, for example, the rate of acceleration being regulated by valves 94 and 102 respectively which limit the maximum pressure which may be built up in lines 87 and 88. It will ordinarily be desirable to bring the brushes to full operating speed as rapidly as possible (the limiting factor being wear and tear on the equiprnent) when the work is being traversed between the brushes at such time. When, however, rotation of the brushes is to be initiated, or the direction of rotation reversed, when not in engagement with the work, as after passage of the trailing end of the length of strip, there will be no particular advantage in accelerating so rapidly and it will normally be preferred to take several seconds more to bring the brushes up to speed and thereby reduce wear. The fluid drive utilized in accordance with this invention, however, is, as indicated, capable of extremely rapid acceleration and deceleration and this is often a great practical advantage, especially when thebrushes are maintained more or less in contact with the work during the reversal period.

After a certain period of operation, which will vary depending on such factors as the type'ofbrush material employed, the rate of operation, the operating pressures imposed and the type of work involved, the brush bristle ends comprising the work face of the brushes become appreciably dulled and it is desired automatically to reverse the direction of rotation of such brushes to compensate for this fact. Such reversal is accomplished here by using a conventional time delay relay for the relay 118 and setting the same for the desired running interval which may, for example, be three minutes. Accordingly, upon expiration of such preset time interval, relay 118 is automatically de-energized, thereby closing. contacts 118A and opening contacts 118B. Closure of contacts 118A again energizes relay 120, whereby the condition of lights 123 and 124 is reversed, while opening of contacts 118B causes relays 131 and 132 to'be de'energized. Such deenergization of relay 131 completes circuit 125 to energize coil 103A of valve 103 and opens circuit 133 to deenergize' the other coil 103B of such valve. Circuit 134 is opened to decnergize solenoid 141 of valve 101A. At the same time, de-energization of relay 132 completes circuit 126 to energize coil 95A of valve 95 andopen the circuit 135 of the other coil 95B of this valve. Solenoid 142 of valve 93A is also de-energized by such de-energization of relay 132.

A braking cycle is thus initiated whereby the brushes 52 and 53 are brought to a halt prior to reversal of the direction of rotation. The shifting of solenoid valve 95 causes the control oil pressure to be shunted from valve 94 to valve 96 which then controls the pressure in line 87 at a pressure sufiicient to maintain the oil head of the fluid motor but at much below normal running pressure. Of course the' shifting of valve 103 has likewise shunted control pressure of line 88 from valve 102 to valve 104 which thereupon assumes control in like manner.

Therefore, no consequential energy input is now being delivered to the respective hydraulic motors 49 and 72, and the brushes 53 and 52 continue to rotate merely as the result of their own momenum.

De-energization of the coil 142 places braking valve 93 in the line 92 to restrict return flow through the same, thereby building up a high back pressure tending to brake hydraulic motor 49 and brush 53 turning therewith. Similarly, the de-energization of coil 141 of valve 101A renders braking valve 101 operative to restrict return flow of fluid in the line 99 and also to build up a high back pressure effective to brake hydraulic motor 72 and brush 52 turning therewith. The two brushes are accordingly quickly and simultaneously brought to a stop.

At the time relays 131 and 132 are thus de-energized, at the end of such predetermined three minute time period, for example, contacts 131A and 132E are opened thereby causing the coil of relay 119 to be de-energized. Such relay is likewise a time delay relay here effective to maintain the conditions controlled thereby for a predetermined interval subsequent to its energization and de-energization. Accordingly, when contacts 131E and 132E are opened as above described, relay 119 is not immediately efiective to open contacts 119A but such contacts will 10 open upon expiration. of such predetermined interval which may, for example, be on the order of two seconds, and will be selected to have a duration slightly less than the period which would be required to bring the brushes to a full halt. In order to avoid an overly severe shock to' the system, it is important that valves 91 and 100 should not be shifted to reverse the flow of hydraulic flow to the motors until the rapidly rotating brushes (each of which may, for example, weigh 700 pounds) have been substantially braked. Relay 119 is so located in the system as to be equally efiective as a safety factor of this nature when the system is under manual as well as automatic control.

Opening of the contacts 119A will be of course result in de-energization of relay 122 to open circuits 127 and 129, whereby relays 137 and 139 are now de-energized. Holding contacts 137A and 139A for such relays respectively open. Contacts 137B open circuit 138 to de-energize the coil 100B, while contacts 139B open to interrupt circuit 140 and thereby de-energize coil 91B. As a result, valves 91 and 100 are fully de-energized and move to their normal center positions, by the usual centering springs, wherein lines 87, 89, and 92 are all directly interconnected as are lines 88, 98, 99 and line 143. The fluid pressure systems for the two motors are accordingly now each in equilibrium.

The de-energization of relay 122 also serves to open contacts122C to interrupt both circuits 125 and 126 and .de-energize coils 103A and A respectively therein.

Valves 95 and 103 are likewise now completely de-energized and move to spring centered positions in which valve 95 shunts the control pressure for valve 94 to the tank and'valve 103 shunts the pressure for valve 102 to the tank. The pressure in all the lines is accordingly now very low, being determined merely by the line resistance.

Energization of relay has also closed contacts 120C and opened contacts 120D to energize relays 144 and 145, such relays now to be used in lieu of relays 131 and 132.

Energization of relay 144 closes contacts 144E while energization of relay 145 closes contacts 145E, such contacts being connected in parallel in the circuit of relay 119 and closure thereof energizing such relay. Such operation of relay 119 results in energization of relay 122 as aforesaid and this conditions circuits 127, 128, 129 and 130. Since contacts 144A and 145A have been closed, circuits 128 and are completed to energize relays 146 and 147. Energization of such relays 146 and 147 closes holding contacts 146A and 147A respectively therefor and also closes contacts 146B and 147B with consequent energization of solenoid coils 100A and 91A. Valve 91 is thus actuated to connect line 87 to line 90 and line 89 to line 92, while such operation of valve 100 connects line 88 to line 99 and line 98 to line 143. The hydraulic motors 49 and 72 are accordingly rotated in the reverse direction.

Contacts 14413 in circuit 125 of the coil 103A have opened and contacts B in the circuit 126 of coil 95A have likewise opened. At the same time, contacts 144C and 145C close to energize coils 103B and 95B respectively to operate valves 103 and 95 to their positions in which pressure regulating valves 102 and 94 are operatively connected to the lines 88 and 87. Full operating pressure is accordingly again rapidly built up in such lines with resultant rapid acceleration of the brushes 52 and 53 to full operating speed in directions of rotation opposite to those in which they were previously being driven. This, however, can only be achieved with simultaneously shunting the braking valves 101 and 93 which is accomplished by closure of contacts 144D and 145D to produce energization of coils 141 and 142.

While the preferred brush material will very generally be crimped steel Wire, this will vary depending on the particular operation involved and nylon coated wire, wire having a Knoop hardness in excess of 600, Tampico fiber, cord, and other materials may all be employed on occa- 11 sion. Cooling and other fluids may be fed to the brushes internally thereof as described in Peterson Patent No. 2,680,938, for example. Dudco dual-vane fluid'motors manufactured by Dudco Division of The New York Air Brake Company have proven particularly satisfactory as 'drive means for the brushes. Very generally the brushes will be driven on the order of 4,00010,000 surface feet per minute. If the brush stand is simultaneously reciprocated transversely of the path of travel of the work,

this may be at a slow rate of only three return reciprocations per minute.

It will be seen that I have provided a smooth, responsive, easily controlled brush drive capable of handling very large and heavy brushes and periodically reversing their direction of rotation in an extremely short period of time, with minimum shock. My new brush mounting facilitates speedy brush change-over with minimum down time of the line in which the stand is used.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

1 therefore particularly point out and distinctly claim as my invention:

1. In control means for a reversible rotary fluid motor adapted to be connected in driving relationship to a rotary tool having a substantial angular momentum such as a rotary brush; a fluid pressure source for driving said motor, valve means adapted selectively to connect said pressure source to opposite sides of said motor to drive said motor in opposite directions, second valve means operable to divert fluid flow from said source away from said motor substantially to reduce the driving force applied to said motor, a flow control valve operable to constrict fluid flow from said motor to brake the latter, and automatic control means operative sequentially to actuate said second valve means to divert fluid flow from said motor, to actuate said flow control valve to constrict fluid flow from said motor to brake the latter, to shift said first valve means to connect said pressure source to the other side of said motor to reverse the direction of rotation of the latter, and to open said flow control valve and actuate said second valve again to direct full desired fluid flow from said source to said motor.

2. The mechanism of claim 1 including a pressure regulating valve interposed between said source and motor to limit maximum fluid presstue delivered to said motor.

3. The method of operating a reversible rotary fluid motor adapted to drive a rotary tool having a substantial angular momentum which comprises periodically reducing fluid flow to such motor, constricting fluid flow from such motor to brake the latter and thus such tool, shifting fluid supply connections ,to such motor to reverse the direction of rotation of the latter, resuming full desired fluid flow to such motor, and resuming free fluid flow from such motor, such indicated operations being timecontrolled to occur at frequent predetermined intervals properly to control such tool wear.

4. In control means for a reversible rotary fluid motor adapted to be connected in driving relationship to a rotary tool having a substantial angular momentum such as a rotary brush; a fluid pressure source for driving said motor, reversing valve means operable selectively to connect said source and motor to drive the motor in opposite directions, means operative periodically to reduce the fluid flow to said motor, constricting valve means operative to reduce fluid flow from said motor cooperating with said means operative to reduce fluid flow to said motor to brake said motor and thus such tool, means automatically to shift said reversing valve to drive said motor in the opposite direction after the angular momentum of such tool has been substantially reduced, and means automatically operative to resume full fluid flow to and from said motor after the shifting of said reversing valve means.

References Cited in the file of this patent UNITED STATES PATENTS 660,317 Sims Oct. 23, 1900 1,934,633 Taylor Nov. 7, 1933 1,972,462 Schafer Sept. 4, 1934 1,990,052 Sosa Feb. 5, 1935 2,157,707 Keel May 9, 1939 2,158,694 Fenton May 16, 1939 2,176,939 Woolford Oct. 24, 1939 2,190,939 Ernst Feb. 20, 1940 2,218,913 Hughes Oct. 22, 1940 2,279,608 Wood Apr. 14, 1942 2,285,208 lohntz June 2, 1942 2,365,748 Curtis Dec. 26, 1944 2,376,212 Warren May 15, 1945 2,636,200 Peterson Apr. 28, 1953 2,674,854 Church Apr. 13, 1954 2,709,142 Durst May 24, 1955 2,737,158 Seybold et a1 Mar. 6, 1956 2,751,822 Schlitz June 26, 1956 2,756,546 Barhorst July 31, 1956 

